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Biology for IGCSE & O level - Gas Exchange In Humans (Section 1)

1
Why is the surface area of the lungs so large?
Answer
(B)
To allow for efficient gas exchange.
2
Which process occurs in the alveoli?
Answer
(B)
Gas exchange.
3
What are the gases exchanged in alveoli?
Answer
(C)
Oxygen and carbon dioxide
4
Which of the following is a part of the upper respiratory system?
Answer
(D)
Nose
5
What is the primary stimulus for increasing the rate and depth of breathing during exercise?
Answer
(B)
Increased carbon dioxide levels in the blood.
6
Which of the following statements best describes the relationship between breathing rate and exercise?
Answer
(C)
Breathing rate increases during exercise.
7
Which of the following best describes the difference in composition of inspired and expired air?
Answer
(B)
Inspired air has less carbon dioxide and more oxygen than expired air.
8
What is the role of cartilage in the trachea?
Answer
(C)
To provide structural support, keeping the airway open.
9
What is the function of the cilia in the respiratory system?
Answer
(B)
To remove dust and pathogens.
10
Which of the following statements is correct about the gas exchange?
Answer
(A)
Carbon dioxide diffuses into the alveoli, oxygen into the capillaries.
11
Which structure within the respiratory system is primarily responsible for gas exchange?
Answer
(C)
Alveoli
12
Which of the following is the first structure air passes through during inhalation?
Answer
(B)
Nose
13
Which gas is absorbed from the alveoli into the bloodstream?
Answer
(C)
Oxygen
14
During strenuous exercise, which of the following respiratory adaptations would you expect to observe?
Answer
A
C
15
Which gas is more concentrated in inhaled air than in exhaled air?
Answer
(B)
Oxygen
16
In the context of gas exchange, what is the primary function of the capillaries?
Answer
(B)
To transport oxygen and carbon dioxide to and from the alveoli.
17
Which of the following is the correct order of air flow through the respiratory system during inhalation?
Answer
(A)
Nose → Trachea → Bronchi → Bronchioles → Alveoli
18
What are the by-products of respiration that are taken to the lungs and then exhaled?
Answer
(C)
Carbon dioxide and water
19
What is the relationship between the diaphragm and the chest cavity during inhalation?
Answer
(C)
Diaphragm contracts, chest cavity volume increases.
20
What are the functions of the intercostal muscles?
Answer
B
D
21
Which of these is the order of air passage after the mouth?
Answer
(B)
Pharynx -> Trachea -> Lungs -> Bronchioles -> Alveoli
22
What happens to the intercostal muscles during inhalation?
Answer
(B)
They contract, lifting the ribs upwards and outwards.
23
During exhalation, the diaphragm ____ and the volume of the chest cavity ____.
Answer
(D)
relaxes, decreases
24
Which of the following processes occurs during inspiration?
Answer
(D)
Air pressure in the chest cavity decreases
25
What is the primary function of surfactant in the alveoli?
Answer
(B)
To reduce surface tension.
26
Which part of the brain is responsible for controlling the rate and depth of breathing?
Answer
(C)
Medulla oblongata
27
What is the function of the diaphragm in breathing?
Answer
(C)
It controls the volume of the chest cavity.
28
Which of the following are involved in the process of breathing (ventilation)?
Answer
A
C
D
29
Which structure delivers air into the lungs?
Answer
(B)
The trachea
30
Which of the following is an accurate comparison of inspired and expired air?
Answer
A
C
D
31
Which of the following is an accurate statement about the composition of exhaled air?
Answer
A
B
32
In which direction does the oxygen move during gas exchange?
Answer
(B)
From the alveoli to the capillaries
33
What is the role of the bronchioles in the respiratory system?
Answer
(C)
To connect the trachea to the alveoli.
34
The volume of air breathed in a single breath is called what?
Answer
(A)
Tidal volume
35
Which of the following correctly describes the movement of the diaphragm and the chest volume during inspiration?
Answer
(B)
Diaphragm contracts; chest volume increases.
36
What role does the brain play in the process of breathing?
Answer
A
C
37
What are the key features of the alveoli that optimize gas exchange?
Answer
A
B
38
What causes the increase in the rate and depth of breathing during exercise?
Answer
(A)
Decreased blood pH.
39
What happens to the concentration of carbon dioxide in the blood during exercise?
Answer
(B)
Increases
40
What is the role of the epiglottis?
Answer
(B)
To close off the trachea during swallowing.
41
What happens to the air pressure inside the chest cavity during inhalation?
Answer
(A)
It decreases.
42
What type of blood vessel surrounds the alveoli?
Answer
(C)
Capillaries
43
During which process does the volume of the chest cavity increase?
Answer
(B)
Inhalation
44
What happens to the alveoli during exhalation?
Answer
(B)
They contract
45
What is the purpose of breathing?
Answer
(B)
To provide oxygen for the cells and remove carbon dioxide.
46
What is the main site of gas exchange in the lungs?
Answer
(C)
Alveoli
47
Which of the following correctly describes the volume changes during expiration?
Answer
(C)
Rib cage moves down, volume decreases
48
What change in the concentration of gases occurs during gas exchange in the alveoli?
Answer
(D)
Oxygen increases and carbon dioxide decreases.
49
Which part of the respiratory system is responsible for warming and moistening the air before it reaches the lungs?
Answer
(C)
Nose
50
Which of the following is an effect of exercise on breathing?
Answer
(B)
Breathing rate increases.